PHILADELPHIA (AP) -- Philadelphia police said Friday they're seeking witnesses after a gunman fired into a crowd of people surrounding the tour bus of rapper French Montana, killing one person and injuring another, and prompting others in the crowd to return fire.

The shooting happened late Thursday night as the bus, followed by several cars loaded with friends and family, arrived at a hotel near Penn's Landing for a post-concert party after the rapper had headlined a sold-out show at the Theatre of Living Arts.

A black sedan with tinted windows pulled up and someone fired shots into the crowd from a passenger side window, Homicide Capt. James Clark said. Two people in the crowd fired back, Clark said, and police were mulling whether to file charges against them.

The New York rapper and members of his entourage were interviewed at police headquarters and are cooperating in the investigation, but police don't know if they were targeted, Clark said.

On Friday evening, French Montana took to Twitter to express sympathy for the victims. He also tweeted that his bus was merely located "in the vicinity of the incident."

"I had a peaceful concert and was not involved," he wrote.

Investigators are searching for any surveillance footage that may provide clues.

"We believe someone saw something," Clark said. "It could have been a lot more tragic."

The man killed was identified by police as 26-year-old Jowann King, of Flushing, N.Y. Police did not release the name of the man who was injured.

French Montana, a Morocco-born rapper whose real name is Karim Kharbouch, posted a photo on Twitter showing a police officer interviewing a person after the shooting, and also posted photos of himself with Philadelphia rapper Meek Mill at the show.

Mill was on the tour bus Thursday night, Clark said.

Montana was scheduled to play Brighton Music Hall in Boston on Friday night as part of a tour to promote his upcoming debut album, "Excuse My French," which features Nicki Minaj. However, the venue's website posted a notice Friday evening saying the show was canceled.

Last month, three people were killed and five injured in a shootout and crash on the Las Vegas strip; police think that shootout may have started as an argument at the valet area of the upscale Aria resort-casino the same night Montana was playing at Aria's signature nightclub, Haze.